The Nasdaq and the S&P 500 slipped on Thursday as vaccine makers fell after President Joe Biden announced plans to back intellectual property waivers on COVID-19 shots, but losses were capped by an upbeat jobless claims report.
Shares in Pfizer Inc, Moderna Inc, Johnson & Johnson and Novavax Inc, all involved in the making of COVID-19 vaccines, fell between 0.2% and 9.3%.
The declines were triggered after Biden said he had backed a World Trade Organization waiver for vaccine intellectual property to enhance the fight against the pandemic.
The S&P 500 healthcare sector slipped 0.5%, while the Nasdaq Biotechnology index dropped 1.3%.
Moderna also raised its 2021 sales forecast for its COVID-19 vaccine, reflecting demand from countries looking to return to normalcy through rapid inoculation.
"It could clearly reduce potential revenues some of these firms were expecting to generate from licensing their patents," said Neil Wilson, chief market analyst at Markets.com.
Shares of highly valued technology-related stocks like Microsoft Corp, Apple Inc, Alphabet Inc and Amazon.com Inc were trading flat to lower.
The S&P 500 technology sector fell 0.4%, while the Philadelphia SE Semiconductor index dropped 0.6%.
A Labor Department report showed fewer Americans filed new claims for unemployment benefits last week as the labor market's recovery gains steam amid an economic boom.
Initial claims for state unemployment benefits totaled a seasonally adjusted 498,000 for the week ended May 1 compared to 590,000 in the prior week.
Investors are awaiting more comprehensive non-farm payrolls data on Friday to get clues on strength of the labor market and potentially the US Federal Reserve's stance on monetary policy.
"Today's read is another proof point that we're one step closer to full economic recovery, sooner than some may have expected," said Mike Loewengart, managing director of investment strategy at E*TRADE Financial.
"So as we see some serious momentum building on the jobs front, all eyes will be on how this plays into action taken by the Fed, if any."
At 9:56 a.m. ET, the Dow Jones Industrial Average was up 63.84 points, or 0.19%, at 34,294.18, the S&P 500 was down 3.95 points, or 0.09%, at 4,163.64 and the Nasdaq Composite was down 62.12 points, or 0.46%, at 13,520.30.
Among other stocks, ViacomCBS Inc rose 1.4% after reporting quarterly revenue that beat Wall Street estimates.
Regeneron Pharmaceuticals Inc rose 1.1% after the drugmaker reported a 78% rise in first-quarter profit, helped by a robust recovery in demand for its eye drug Eylea.
Uber Technologies Inc fell 5.5% as it signaled it would pay drivers more to get cars back on the road and disclosed a $600 million charge to provide UK drivers with benefits.
Declining issues outnumbered advancers for a 1.03-to-1 ratio on the NYSE and for a 1.95-to-1 ratio on the Nasdaq.
The S&P index recorded 81 new 52-week highs and no new low, while the Nasdaq recorded 68 new highs and 58 new lows.